This invention relates to heart valve prostheses for replacement of defective natural valves and more particularly to heart valve prostheses using a pair of pivoting valve members, preferably ones which are arcuate in cross section.
Various types of heart valve prostheses have been developed which operate hemodynamically as a result of the pumping action of the heart. Some of these valves which have been used employ a ball-and-cage arrangement, whereas others have used a disc-type arrangement for the valve member. Exemplary of a disc of the free floating type is U.S. Pat. No. 3,543,411, issued Oct. 20, 1970. Various disc-type valves having a pivotal arrangement have been developed, such as that shown in U.S. Pat. No. 3,546,711 to Bokros, issued Dec. 15, 1970, and that shown in U.S. Pat. No. 3,859,668, issued Jan. 14, 1975.
Disc-type heart valves have also been developed which use two members or leaflets, instead of a single disc, which leaflets rotate about parallel axes as a part of the opening and closing of the valve. British Pat. No. 1,160,008 shows an early version of such a valve, and U.S. Pat. No. 4,078,268, issued Mar. 14, 1978, shows a later version.